Markers of Renal Function in Older Adults Completing a Higher Protein Obesity Intervention and One Year Later: Findings from the MEASUR-UP Trial.

Increases in rates of obesity in the older population are hastening the development of chronic illnesses, including chronic kidney disease (CKD). However, obesity reduction in older adults is besought with concerns about the long-term benefit/risk, especially regarding loss of muscle mass and its impact on function. Higher protein intakes have been advocated to help offset the tendency for loss of muscle during weight reduction but this raises concerns about possible negative effects on older kidneys. We assessed markers of renal function in venous blood samples collected during a six-month randomized controlled weight loss trial of higher protein intake in obese (n = 67; BMI ≥ 30 kg/m2 ) older (≥60 years) adults with physical frailty and age-normal renal status (glomerular filtration rate [GFR] ≥ 45); the Control diet (0.8 g protein/kg body weight/day; n = 21) was compared to a protein-enhanced (1.2 g/g protein/kg body weight/day with 30 g protein/meal; n = 41; Protein) diet. Results showed no group effect of the Protein treatment on markers of renal function (estimated GFR, blood urea nitrogen, and creatinine), either upon intervention completion or one year later. Our findings align with literature support for the benefits of higher protein in the diets of older individuals during obesity reduction and help to confirm the safety of moderate increases in protein intake during weight loss in this population.